xen-devel

[Top] [All Lists]

[Xen-devel] [PATCH] Enable TSC_RELIABLE for AMD servers

from [Dan Magenheimer]

[Permanent Link][Original]

To:	"Xen-Devel (E-mail)" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject:	[Xen-devel] [PATCH] Enable TSC_RELIABLE for AMD servers
From:	Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
Date:	Tue, 20 Oct 2009 08:05:25 -0700 (PDT)
Cc:	mark.langsdorf@xxxxxxx, Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Delivery-date:	Tue, 20 Oct 2009 08:07:39 -0700
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxxx
List-help:	<mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id:	Xen developer discussion <xen-devel.lists.xensource.com>
List-post:	<mailto:xen-devel@lists.xensource.com>
List-subscribe:	<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe:	<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

(Mark, please ack)

Enable TSC_RELIABLE for AMD servers

Except for a published BIOS errata on family 11h processors,
all AMD servers that have the Invariant TSC bit set have
a reliable TSC so Xen should not write to the TSC.

Signed-off-by: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>


diff -r d7d7f978d704 xen/arch/x86/cpu/amd.c
--- a/xen/arch/x86/cpu/amd.c    Tue Oct 20 14:36:01 2009 +0100
+++ b/xen/arch/x86/cpu/amd.c    Tue Oct 20 08:55:53 2009 -0600
@@ -465,6 +465,8 @@ static void __devinit init_amd(struct cp
                if (c->x86_power & (1<<8)) {
                        set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
                        set_bit(X86_FEATURE_NONSTOP_TSC, c->x86_capability);
+                       if (c->x86 != 0x11)
+                               set_bit(X86_FEATURE_TSC_RELIABLE, 
c->x86_capability);
                }
        }

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

[More with this subject...]

<Prev in Thread]	Current Thread	[Next in Thread>
[Xen-devel] [PATCH] Enable TSC_RELIABLE for AMD servers, Dan Magenheimer <= RE: [Xen-devel] [PATCH] Enable TSC_RELIABLE for AMD servers, Langsdorf, Mark

Previous by Date:	Re: [Xen-devel] Re: PCI tuners with XEN, Mr. Teo En Ming (Zhang Enming)
Next by Date:	[Xen-devel] [PATCH] implement pci coldplug for stubdoms, Stefano Stabellini
Previous by Thread:	[Xen-devel] PCI tuners with XEN, William Eder
Next by Thread:	RE: [Xen-devel] [PATCH] Enable TSC_RELIABLE for AMD servers, Langsdorf, Mark
Indexes:	[Date] [Thread] [Top] [All Lists]